1. Technical Field
The present invention relates to package structures, and more particularly, to a package structure of an optical module.
2. Description of Related Art
At present, an optical proximity sensing module is regarded as a mainstream technology choice for use with the new-generation smart electronic devices (such as smartphones). If the electronic device is brought close to the human ear (for face recognition) or put in a pocket, the optical proximity sensing module will turn off the screen display of the electronic device right away to save power and prevent an inadvertent touch on the screen display, thereby enhancing ease of use. The optical proximity sensing module comprises a light-emitting chip (such as a light-emitting diode, LED) for emitting a light beam. The light beam reflects off an object surface to fall on a light-admitting chip and convert into an electronic signal for subsequent processing. For instance, Taiwan patent M399313 discloses a proximity sensing package structure which comprises a base, a dam extending vertically and enclosing the base, and a lid disposed on the dam, so as to form a receiving space, wherein the receiving space has therein a partition board for dividing the receiving space, such that a light-emitting chip and a light-admitting chip can be separately disposed on a substrate to shun mutual light beam-related interference which might otherwise result in deterioration of product performance.
However, smart electronic devices nowadays have a trend toward reduction of thickness. The packaging process of the aforesaid patent requires that a lid be fixed to a dam and a partition board from above; as a result, evidently, the package structure incurs high material costs. Furthermore, the lid is of a considerable thickness, which restrains the extent of reduction in the total package structure height.